Ionization-induced frequency shifts in intense femtosecond laser pulses

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of the Optical Society of America, Part B: Optical Physics; (United States)

DOI:https://doi.org/10.1364/JOSAB.9.002032· OSTI ID:6897668

Penetrante, B M; Bardsley, J N ^[1]; Wood, W M; Siders, C W; Downer, M C ^[2]

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1. High Temperature Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

Electromagnetic plasma computer simulations are used to analyze the frequency shifts caused by the ionization of atmospheric-density noble gases during interaction with intense femtosecond laser pulses; the results are presented and compared with experimental data. The simulations trace the temporal evolution of plasma growth during the femtosecond ionizing pulse and calculate the resulting self-induced blue shift of the ionizing pulse spectrum. Variations with pulse intensity, gas pressure, and gas species are calculated. The relative contributions of strong-field ionization and electron-impact ionization on the frequency shifts are discussed. The simulations provide qualitative explanations of most of the features observed experimentally in the blue-shifted spectra. The technique of spectral blue shifting intense femtosecond laser pulses provides a new diagnostic tool for studying strong-field ionization and laser-induced breakdown in dense plasmas.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6897668
• Journal Information: Journal of the Optical Society of America, Part B: Optical Physics; (United States), Journal Name: Journal of the Optical Society of America, Part B: Optical Physics; (United States) Vol. 9:11; ISSN JOBPDE; ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUATIONS
FLUIDS
GASES
HOMOGENEOUS PLASMA
IONIZATION
LASER RADIATION
MAXWELL EQUATIONS
MEDIUM PRESSURE
NONMETALS
ONE-DIMENSIONAL CALCULATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PHOTOIONIZATION
PLASMA
PLASMA SIMULATION
PULSES
RADIATIONS
RARE GASES
SIMULATION
SPECTRAL SHIFT